Message about using --parallel, and how other CWL runners are available.

[tetron]

Was having a discussion about how some people have trouble distinguishing between the capabilities of cwltool and the broader CWL ecosystem. It occurred to me that we could just tell people, clearly, to look elsewhere (and where to look).

Also added a message about the existence of the --parallel option.

INFO /home/peter/work/cwltool/venv3/bin/cwltool 3.1.20220519125739
INFO Resolved 'revsort.cwl' to 'file:///home/peter/work/cwl-v1.2/tests/revsort.cwl'
INFO Using default serial job executor.  Use `cwltool --parallel` to run multiple steps at a time.
INFO [workflow ] start
INFO [workflow ] starting step rev
...
INFO [job sorted] Max memory used: 0MiB
INFO [job sorted] completed success
INFO [step sorted] completed success
INFO [workflow ] completed success
INFO Need to grow beyond `cwltool` and scale up your workflows on a HPC cluster, or in the cloud?
INFO CWL workflows are portable and run on many commercial and open source platforms.
INFO Visit https://www.commonwl.org/implementations/ to learn more.
{
    "output": {
        "location": "file:///home/peter/work/cwl-v1.2/tests/output.txt",
        "basename": "output.txt",
        "class": "File",
        "checksum": "sha1$b9214658cc453331b62c2282b772a5c063dbd284",
        "size": 1111,
        "path": "/home/peter/work/cwl-v1.2/tests/output.txt"
    }
}
INFO Final process status is success

[codecov]

Codecov Report

Merging #1671 (ae06c52) into main (c23a9ed) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #1671      +/-   ##
==========================================
+ Coverage   66.86%   66.87%   +0.01%     
==========================================
  Files          93       93              
  Lines       16648    16664      +16     
  Branches     4420     4422       +2     
==========================================
+ Hits        11131    11144      +13     
- Misses       4376     4378       +2     
- Partials     1141     1142       +1     

Impacted Files	Coverage Δ
cwltool/executors.py	83.18% <100.00%> (+0.60%)	⬆️
cwltool/cwltool/job.py	62.64% <0.00%> (-0.20%)	⬇️
cwltool/cwltool/executors.py	65.08% <0.00%> (+0.35%)	⬆️

---

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[kinow]

Minor comment about the text about other runners, but I liked the idea of telling users about other runners. +1 for the parallel/serial message too.

[kinow]

👍

[kinow]

Maybe shorten it a bit? Perhaps dropping the first line, leaving just the part about "CWL workflows are portable and run .... Visit https:///...".

[kinow]

Argh, sorry, didn't notice the auto-merger was on here 😥

[kinow]

@mr-c big ops from me here. I can't see the button to un-do the merge. Could you do it, or should I send a new PR reverting it? Sorry about the mess!

[kinow]

Or if you have access to that button, @tetron 🙏